A typical brassiere comprises a pair of front cups that are connected together at their adjacent inner edges and respective side straps extending from outer edges of the cups back around the wearer and there forming so-called wings. Normally respective shoulder straps extend up from upper edges of the cups, over the wearer's shoulders, and down to the wings at the back where they are secured.
The ends of the wings overlap in the center of the wearer's back and are there joined together by a releasable closure or fastener that has an outer part provided on an inner face of the outer wing and a complementary inner part on an outer face of the inner wing, that is the wing bearing directly on the wearer's back. Such a closure is typically one or more hooks on the outer wing and one or more eyes on the inner wing, normally a row of eyes to allow some adjustability. Other arrangements of male and female parts are often also used.
The hardest part in donning such an undergarment is securing the two parts of the back fastener together. When this is done behind the back, the user cannot see it and the user's hands are inverted and arms are twisted back into a position that is uncomfortable and, in fact, impossible to assume for some. Since most brassieres have between two and five rows of hooks, these garments are much more difficult to close, so that normally the user fastens the wings of the undergarment together in the front and then wrestles the garment around to the back before it is actually donned, a much more complex procedure than simply pulling the front on and then closing the wings together behind the back.
U.S. Pat. No. 6,163,938 of Weber-Unger discloses a catch for a drop cup of a maternity brassiere. There the two closure parts are provided with respective permanent magnets exposed at the inner face of the outer wing and the outer face of the inner wing. The magnets are positioned such that the magnets attract each other and center on each other in a position with the male and female parts of the closure at least partially interengaged. The function of these magnets is to hold the closure in this partially closed position when there is no tension on the wings pulling them apart. To open or close the drop cup, the user must still carefully align and fit together the two closure parts, but this is a simple operation since it is in the front.